One such dispute, which can trace its roots back to the summer of 2013, has finally reached a conclusion, as the U.S. Department of Justice (DOJ) has closed its investigation as to whether Samsung can use standards-essential patents to block Apple products, deciding that no further investigation is necessary.

Standards-essential patents cover technology that is foundational. Without these patents, certain technology would not work. Owners of such patents are expected to allow competitors to license them in fair, reasonable and non-discriminatory fashion, though the details of these agreements are often the subject of dispute.

Back in June of 2013, the International Trade Commission (ITC) banned the import of certain iPhone and iPad devices, ruling that Apple had infringed on a Samsung patent that the Korean company stated was essential to 3G wireless technology. The ban didn’t last long, however, as the Obama administration struck it down, stating that it was not in the public interest and expressing concern that standards-essential patents could be used as weapons to cripple competition.

The Antitrust Division of the DOJ looked closely at whether Samsung was using these essential patents to create a block that it could use as an advantage in obtaining extreme licensing terms. The DOJ worked with its counterparts in the European Commission throughout the probe, and is expected to rule on the matter shortly.

The matter between Apple and Samsung is far from over, however, and is a clear example of how patent trolls are not the only source of litigation in the IP world. The big boys are more than happy to slug it out with each other.